The present invention generally relates to the field of extracorporeal blood processing and, more particularly, to methods and apparatus which may be incorporated into an apheresis system (e.g, blood component collection, therapeutic).
One type of extracorporeal blood processing is an apheresis procedure in which blood is removed from a donor or patient, directed to a blood component separation device (e.g, centrifuge), and separated into various blood component types (e.g, red blood cells, white blood cells, platelets, plasma) for collection or therapeutic purposes. One or more of these blood component types are collected (e.g, for therapeutic purposes), while the remainder are returned to the donor or patient.
A number of factors affect the commercial viability of an apheresis system. One factor relates to the operator of the system, specifically the time and/or expertise required of an individual to prepare and operate the apheresis system. For instance, reducing the time required by the operator to load and unload the disposables, as well as the complexity of these actions, can increase productivity and/or reduce the potential for operator error. Moreover, reducing the dependency of the system on the operator may lead to reductions in operator errors and/or to reductions in the credentials desired/required for the operators of these systems.
Donor-related factors may also impact the commercial viability of an apheresis system and include donor convenience and donor comfort. For instance, donors typically have only a certain amount of time which may be committed to visiting a blood component collection facility for a donation. Consequently, once at the collection facility the amount of the donor""s time which is actually spent collecting blood components is another factor which should be considered. This also relates to donor comfort in that many view the actual collection procedure as being somewhat discomforting in that at least one and sometimes two access needles are in the donor throughout the procedure.
Performance-related factors continue to affect the commercial viability of an apheresis system. Performance may be judged in terms of the xe2x80x9ccollection efficiencyxe2x80x9d of the apheresis system, which may in turn reduce the amount of donation time and thus increase donor convenience. The xe2x80x9ccollection efficiencyxe2x80x9d of a system may of course be gauged in a variety of ways, such as by the amount of a particular blood component type which is collected in relation to the number of this blood component type which passes through the apheresis system. Performance may also be evaluated based upon the effect which the apheresis procedure has on the various blood component types. For instance, it is desirable to minimize the adverse effects on the blood component types as a result of the apheresis procedure (e.g, reduce platelet activation).
The present invention generally relates to extracorporeal blood processing. Since each of the various aspects of the present invention may be incorporated into an apheresis system (e.g, whether for blood component collection in which xe2x80x9chealthyxe2x80x9d cells are removed from the blood or for therapeutic purposes in which xe2x80x9cunhealthyxe2x80x9d cells are removed from the blood), the present invention will be described in relation to this particular application. However, at least certain of the aspects of the present invention may be suited for other extracorporeal blood processing applications and such are within the scope of the present invention.
An apheresis system which may embody one or more aspects of the present invention generally includes a blood component separation device (e.g, a membrane-based separation device, a rotatable centrifuge element, such as a rotor, which provides the forces required to separate blood into its various blood component types (e.g, red blood cells, white blood cells, platelets, and plasma)). In one embodiment, the separation device includes a channel which receives a blood processing vessel. Typically, a healthy human donor or a patient suffering from some type of illness (donor/patient) is fluidly interconnected with the blood processing vessel by an extracorporeal tubing circuit, and preferably the blood processing vessel and extracorporeal tubing circuit collectively define a closed, sterile system. When the fluid interconnection is established, blood may be extracted from the donor/patient and directed to the blood component separation device such that at least one type of blood component may be separated and removed from the blood, either for collection or for therapy.
A first aspect of the present invention relates to enhancing the ease of loading a blood processing vessel into a channel which is associated with a centrifuge rotor. In one embodiment of this first aspect, the centrifuge rotor includes a blood processing vessel loading aperture in its sidewall which extends only part of the way through the centrifuge rotor and then extends upwardly through the top of the centrifuge rotor. The centrifuge rotor thereby provides an opposing surface to the portion of the loading aperture which may be characterized as laterally extending. The loading aperture within the centrifuge rotor may then be properly characterized as being substantially L-shaped. When the disposable blood processing vessel is inserted into this opening, it is deflected upwardly through the centrifuge rotor. The operator may then grasp the blood processing vessel and load it into the channel.
Another embodiment of this first aspect relates to a drive assembly for a centrifuge rotor assembly. The rotor assembly includes a rotor housing, a channel mounting having a channel associated therewith, and a single gear which rotatably interconnects the rotor housing and channel mounting. Through use of this single gear and by having this single gear be radially offset in relation to the above-described loading aperture in the centrifuge rotor, the access to the loading aperture is not substantially affected by the drive assembly for the centrifuge rotor. For instance, by radially off-setting the single drive gear in relation to a plane which bisects the loading aperture, any counterweights which are used to establish rotational balance of the centrifuge rotor will be disposed so as to not adversely affect access to the loading aperture.
A second aspect of the present invention relates to the cross-sectional configuration of at least a portion of a channel associated with a channel housing which is interconnectable with a blood component separation device. Generally, the channel itself is configured so as to retain the blood processing vessel therein during the apheresis procedure. This is particularly desirable in the case of the blood component collection device being a centrifuge which is operated at high rotational speeds, such as greater than 2,500 RPM and even up to about 3,000 RPM. In one embodiment, for at least a portion of the length of the channel a lip extends partially across an upper portion of the channel.
The lip in this second aspect may be provided by configuring at least one of the inner and outer channel walls with a generally C-shaped cross-sectional configuration. In this case, both the upper and lower portions of the channel having the noted lip would have reduced widths in comparison with the middle portion of the channel. These reduced width upper and lower portions of the channel may receive portions of a blood processing vessel which are sealed together. The channel configuration would then also serve to reduce the stresses experienced by these seals when the blood processing vessel is pressurized during the apheresis procedure.
A third aspect of the present invention relates to a blood processing vessel, and more specifically to a blood processing vessel which may be effectively loaded within a channel. In one embodiment of this third aspect, the blood processing vessel provides a continuous flow path by overlapping and radially off-setting first and second ends and utilizing first and second connectors. The first and second connectors are each positioned between the two ends of the blood processing vessel, communicate with the interior of the blood processing vessel, and when engaged facilitate the loading the blood processing vessel into the channel in the correct position. One of the connectors may be a stub-like structure which extends outwardly from the inner sidewall of the blood processing vessel, while the other connector may be a stub-like structure which extends outwardly from the outer sidewall of the blood processing vessel.
Another embodiment of this third aspect is a blood processing vessel which is particularly useful for the channel described in the second aspect above. In this regard, the blood processing vessel is sufficiently rigid so as to not only be free-standing, but to be loaded into the channel of the second aspect as well. However, the blood processing vessel is still sufficiently flexible so as to be able to substantially conform to the shape of the channel during an apheresis procedure. This is particularly desirable when the channel is shaped to provide one or more desired functions regarding the apheresis procedure.
Once the blood processing vessel is loaded into the channel, at least the blood processing vessel must be primed. In this regard, a fourth aspect of the present invention relates to priming, preferably with blood. A channel associated with a channel housing, which is rotatably interconnected with a centrifuge rotor, includes a first cell separation stage. The first cell separation stage is sized such that a ratio of a volume of the channel which does not have RBCs to a volume of the channel which does have RBCs is no greater than one-half of one less than the ratio of the hematocrit of blood entering the channel to the hematocrit of red blood cells exiting the channel. With this configuration, blood may be used to prime the blood processing vessel when disposed within the channel, and thus the channel may be properly characterized as xe2x80x9cblood-primable.xe2x80x9d
In one embodiment of this fourth aspect, the channel extends generally curvilinearly about a rotational axis of the channel housing in a first direction. The channel includes, progressing in the first direction, the first cell separation stage, a red blood cell dam, a platelet collection area, a plasma collection area, and an interface control region for controlling a radial position of at least one interface between red blood cells and an adjacent blood component type(s) (e.g, a buffy coat of WBCs, lymphocytes, and platelets). Blood introduced into the channel is separated into layers of red blood cells, white blood cells, platelets, and plasma in the first cell separation stage. Preferably, throughout the apheresis procedure and including the priming of the blood processing vessel, only separated platelets and plasma flow beyond the red blood cell dam where the platelets may be removed from the channel in the platelet collection area. This is provided by an interface control mechanism which is disposed in the interface control region of the channel and which maintains the position of the interface between separated red blood cells and the buffy coat such that this condition is maintained.
Although the term xe2x80x9cblood primexe2x80x9d is subject to a variety of characterizations, in each case blood is the first fluid introduced into the blood processing vessel. One characterization of the blood prime is that separated plasma is provided to the interface control region before any separated red blood cells flow beyond the red blood cell dam into the platelet collection area. Another characterization is that blood and/or blood component types occupy the entire fluid-containing volume of the blood processing vessel before any separated red blood cells flow beyond the red blood cell dam into the platelet collection area.
One configuration of the channel which allows for a blood priming of the blood processing vessel when loaded within the channel is one in which the volume of that portion of the channel which principally contains plasma during the apheresis procedure is small in comparison to the volume of that portion of the channel which principally contains red blood cells during the apheresis procedure. This allows plasma to be provided to the interface control region of the channel before red blood cells flow beyond the red blood cell dam into the platelet collection stage to provide the red blood cell-buffy coat interface control function. That degree of xe2x80x9csmallxe2x80x9d of the noted channel portion volume which allows for blood priming may be specifically defined in relation to a reference circle which has its origin on the rotational axis of the centrifuge housing and which intersects the channel at a predetermined location on the red blood cell dam. The volume of the channel which principally contains separated plasma in the apheresis procedure is disposed inside of this reference circle (e.g, VPL) and the volume of the channel which principally contains separated red blood cells in the apheresis procedure is disposed outside of this reference circle (e.g, VRBC). In one embodiment the ratio of VPL/VRBC is no greater than about 0.3, and preferably no greater than about 0.25. This desired ratio may be achieved by having the width of the channel between the platelet collection area and the plasma collection area be less than the width of the channel throughout the first cell separation stage. By utilizing this reduced width, the configuration of the channel between the platelet collection area and the plasma collection area may utilize substantially vertically extending and planar inner and outer channel walls.
A fifth aspect of the present invention relates to priming a blood processing vessel disposed in a channel of a channel housing. Blood is used in the prime and the invention also accommodates for the removal of air from the blood processing vessel during this prime. A donor/patient blood transfer assembly fluidly interconnects the blood processing vessel and a donor/patient, and may include an air receptacle for receiving air which is displaced from the blood processing vessel by the blood priming. The various features associated with the channel of the above-noted fourth aspect of the invention may be utilized in this fifth aspect as well.
A sixth aspect of the present invention relates to blood priming an apheresis system which includes a channel housing having a blood processing channel associated therewith, a blood processing vessel disposed in the channel and which has a blood inlet port, red blood cell outlet port, and an interface control port. The interface control port is used to control the radial position of at least one interface between separated red blood cells and a blood component type(s) disposed adjacent the separated red blood cells.
A method of this sixth aspect includes the steps of rotating the channel housing with the blood processing vessel positioned in its channel, introducing blood into the blood processing vessel to prime the same, and separating the blood into at least red blood cells, platelets, and plasma. The red blood cells are restricted from flowing beyond the red blood cell dam throughout the procedure, including in the priming of the blood processing vessel. In this regard, a flow of plasma is provided to the interface control port before any of the red blood cells are able to flow beyond the red blood cell dam. Once this plasma reaches the interface control port, control is established of the radial position of the interface between the separated red blood cells and the adjacent blood component type(s) such that the potential for red blood cells flowing beyond the red blood cell dam is reduced. One or more of the various features discussed above with regard to the fourth and fifth aspects noted above may be incorporated into this sixth aspect as well.
A seventh aspect of the present invention is a method which may be utilized to prime a blood processing vessel disposed in a channel of a channel housing with blood. In this method, the blood processing vessel is disposed in the channel on the channel housing and a donor/patient blood transfer assembly fluidly interconnects a donor/patient with this blood processing vessel. The method generally includes the steps of initiating the flow of blood from the donor/patient to the donor/patient blood transfer assembly while rotating the channel housing at a first rotational velocity. Once the flow of blood reaches the blood processing vessel, the rotational velocity of the channel housing is increased to a second rotational velocity. Once the entirety of the blood processing vessel contains either blood and/or one or more blood component types, the rotational velocity of the channel housing is once again increased to a third rotational velocity. In one embodiment, the first rotational velocity ranges from about 180 RPM to about 220 RPM, and is preferably about 200 RPM, the second rotational velocity ranges from about 1,800 RPM to about 2,200 RPM and is preferably about 2,000 RPM, and the third rotational velocity ranges from about 2,700 RPM to about 3,300 RPM, and is preferably about 3,000 RPM. Although a three-step approach may be utilized in the practice of the method of this seventh aspect, the centrifuge speed need not stay at a fixed velocity during each of the three xe2x80x9cstagesxe2x80x9d (e.g, the first stage being priming the extracorporeal circuit from the donor/patient to the blood processing vessel, the second stage being priming the blood processing vessel, and the third stage being the remainder of the apheresis procedure). One or more of the various features discussed above with regard to the fourth, fifth and sixth aspects noted above may be incorporated into this seventh aspect as well.
An eighth aspect of the invention relates to priming the apheresis system with blood. The apheresis system includes a channel housing having a channel associated therewith, a blood processing vessel disposed in the channel, a donor/patient blood transfer assembly which fluidly interconnects a donor/patient with the blood processing vessel and which includes a blood reservoir. A method in accordance with this eighth aspect includes performing first and second drawing steps. The first drawing step includes drawing blood from the donor/patient through a first portion of the donor/patient blood transfer assembly and into the blood reservoir. After this first drawing step is terminated, the blood processing vessel is primed with the donor/patient""s blood by performing the second drawing step. The second drawing step includes drawing blood from the donor/patient, through a second portion of the donor/patient blood transfer assembly, through the blood processing vessel, and back into the blood reservoir. One or more of the various features discussed above with regard to the fourth, fifth, sixth, and seventh aspects noted above may be incorporated into this eighth aspect as well.
A ninth aspect of the present invention relates to the introduction of blood into the blood processing vessel such that the blood may be separated into at least two blood component types and further such that at least one of these blood component types may be removed from the blood processing vessel via a blood component outlet port. The blood processing vessel includes two interconnected sidewalls (e.g, substantially planar surfaces which define the main body of the fluid-containing volume of the blood processing vessel) and the blood inlet port extends through one of these sidewalls. Generally, the blood exits the blood inlet port within the interior of the blood processing vessel in a direction which is at least partially in the direction of the primary flow of blood through the channel. This introduction of blood into the blood processing vessel is subject to a number of characterizations. For instance, the introduction may be characterized as the blood exiting the blood inlet port into the interior of the blood processing vessel at an angle of less than 90xc2x0 relative to a reference line extending perpendicularly to the channel wall which interfaces with the blood inlet port. The introduction may be further characterized as exiting the blood inlet port in a direction which is substantially parallel with a direction of flow adjacent the blood inlet port. In one embodiment, red blood cells may actually flow along the outer wall of the blood processing vessel past the blood inlet port such that the noted introduction of blood into the blood processing vessel may be further characterized as reducing the potential for disturbing this flow of red blood cells and/or as reducing an effect on flow characteristics in the area of the blood processing vessel in which blood is introduced. The introduction may be further characterized as exiting the blood inlet port in a direction which is substantially parallel with the sidewall of the blood processing vessel which interfaces with the blood inlet port.
A tenth aspect of the present invention relates to the removal of platelets from the blood processing vessel. This tenth aspect is based upon the blood processing vessel and part of the adjacent channel wall of the channel collectively defining a generally funnel-shaped blood component collect well which collects at least one blood component type flowing thereby (e.g, platelets). In one embodiment, the blood processing vessel includes a blood inlet port and a first blood component outlet port. A support is disposed proximate the blood component outlet port and exteriorly relative to the fluid-containing volume of the blood processing vessel. This support is contoured to direct the desired blood component type(s) toward the blood component outlet port and is in an over-lapping relation with the exterior surface of the blood processing vessel. The support may be separable from the blood processing vessel such that it may be positioned between the blood processing vessel and the associated channel wall after the vessel is loaded into the channel. The support may also be fixedly interconnected with the blood processing vessel in some manner. For instance, the support may be pivotally or hingedly interconnected with the exterior of the blood processing vessel to facilitate loading of the blood processing vessel and/or to allow the support to move into a predetermined position upon pressurization of the blood processing vessel during an apheresis procedure to perform the desired function. Moreover, the support may be integrally formed with the associated blood component outlet port.
In another embodiment relating to this tenth aspect, the channel includes inner and outer channel walls and part of a generally funnel-shaped blood component collect well is formed in at least one of these channel walls. That is, the remainder of the funnel-shaped blood component collect well is defined by the blood processing vessel, such as described above in relation to the first embodiment of this tenth aspect. In order to allow the above-described blood processing vessel to be effectively loaded into the blood processing channel, specifically one of its blood component outlet ports, a blood component outlet port recess extends radially beyond the portion of the blood component collect well defined by the channel wall (e.g, if the well is on the outer wall of the channel, this would be further radially outwardly, whereas, if the well is on the inner wall of the channel, this would be further radially inwardly). This recess may also be configured so as to allow the above-noted contoured support, which interfaces with the exterior of the blood processing vessel, to move into a predetermined position upon pressurization of the blood processing vessel to direct the desired blood component type(s) into the blood component collect port.
In another embodiment of this tenth aspect, a method for processing blood in an apheresis system includes the steps of loading a blood processing vessel in a channel on a channel housing. A contoured support is disposed between the channel and the blood processing channel. When blood is introduced into the blood processing vessel and the channel housing is rotated to separate the blood into various blood component types, a generally funnel-shaped platelet collect well is defined by conforming one part of the blood processing vessel to the channel and by further conforming another part of the blood processing vessel to the shape of the support interfacing with the blood processing vessel. In order to further define this generally funnel-shaped platelet collect well, pressurization of the blood processing vessel may move the support into a predetermined position. For instance, this may then allow the support to direct the platelets toward a platelet collect port on the blood processing vessel.
An eleventh aspect of the present invention relates to a control port which assists in automatically controlling (i.e., without operator action) the location of an interface between red blood cells and a buffy coat relative to a red blood cell dam. The red blood cell dam restricts the flow of separated red blood cells to a platelet collect port. The control port extends through the blood processing vessel and removes plasma and red blood cells as required in order to reduce the potential for red blood cells flowing xe2x80x9coverxe2x80x9d the red blood cell dam to the platelet collect port. The xe2x80x9cselectivexe2x80x9d removal of red blood cells from the blood processing vessel through the control port function is based at least in part upon its position within the channel. That is, the automatic control provided at least in part by the control port is predicated upon the control port assuming a predetermined radial position within the channel. In order to facilitate achieving this predetermined radial position within the channel, the disposition of the control port is provided independently of the thickness of the blood processing vessel. Specifically, the position of the control port is not dependent upon the thickness of the materials which form the blood processing vessel.
The desired objective for the control of this eleventh aspect of the present invention may be affected by interconnecting a support or shield-like structure with the control port and disposing this support over an exterior surface of the blood processing vessel. This support may then be positioned against an interior surface of the channel, preferably within a recess which is specifically designed to receive the support. This support may also be more rigid than the blood processing vessel itself which reduces the potential for any significant change in the radial position of the control port when the blood processing vessel is pressurized (e.g, any radial movement within a slot which receives the control port and which allows the control port to extend within the channel). These support or shield-like members may also be used for other blood inlet/outlet ports on the blood processing vessel to similarly maintain the associated port in a predetermined position and/or to reduce the discontinuity along the part of the channel with which the port interfaces.
A twelfth aspect of the present invention relates to a packing factor associated with the separated blood component types in a separation stage(s) of the blood processing vessel. The packing factor is a number which reflects the degree with which the blood component types are xe2x80x9cpacked togetherxe2x80x9d in the separation stage(s) and is dependent at least upon the rotational speed of the channel housing and the flow rate into the blood processing vessel. The packing factor may be characterized as a dimensionless xe2x80x9cdensityxe2x80x9d of sorts of the blood component types in the separation stage(s).
One embodiment of this twelfth aspect is a method which includes the steps of rotating the channel housing, providing a flow to the blood processing (e.g, the flow includes blood and typically anticoagulant as well), separating the blood into a plurality of blood component types, and adjusting the rotational speed of the channel housing based upon a certain change in the flow rate. Since the packing factor is dependent upon the rotational speed of the channel housing and the flow rate into the blood processing vessel, the methodology of this eleventh aspect may be used to maintain a substantially constant and predetermined packing factor. In this regard, preferably the packing factor is maintained between about 11 and about 15, and preferably about 13.
Another embodiment of this twelfth aspect is a method for processing blood in an apheresis system in which a blood processing vessel is disposed in a channel of a channel housing. The method includes the steps of rotating the channel housing, providing a flow of blood (typically anticoagulated) to the blood processing vessel at a rate ranging from about 40 milliliters per minute to about 70 milliliters per minute, separating the blood into a plurality of blood component types in a first stage of the channel, and removing at least one of the blood component types from the blood processing vessel. Throughout the separating step, a packing factor of at least about 10, and more preferably at least about 10.2, is maintained in the first stage. For flow rates up to about 50 milliliters per minute, the packing factor is more preferably maintained at about 13 which may be achieved by rotating the channel housing at speeds greater than 2,500 RPM and typically closer to about 3,000 RPM.
Another embodiment of this twelfth aspect of the present invention relates to the configuration of a channel associated with a channel housing which is rotatably interconnected with a centrifuge rotor. The channel includes a first cell separation stage and a first blood component collection stage which are separated by a cell dam. At least one type of blood component is separated from remaining portions of the blood in the first cell separation stage and flows beyond the cell dam into the first blood component collection stage, while at least one other type of blood component is preferably precluded from flowing beyond the cell dam into the first blood component collection stage. The width or sedimentation distance of the channel on the end of the first cell separation stage disposed closest to the cell dam is less than the width or sedimentation distance of the channel on the opposite end of the first cell separation stage. In one embodiment, the width/sedimentation distance of the channel in the first cell separation stage is progressively reduced approaching the cell dam. When the above-identified types of packing factors are utilized, this channel configuration may be used to reduce the volume of a buffy coat (white blood cells, lymphocytes, and platelets) between separated red blood cells and platelets in the first stage, and thus reduces the number of platelets that are retained within the first cell separation stage.
A thirteenth aspect of the present invention relates to the rinseback operation at the end of the apheresis procedure in which attempts are made to remove the remaining contents of the blood processing vessel and provide the same back to the donor/patient. In one embodiment, one or more ports of the blood processing vessel, which interface with the sidewall of the blood processing vessel, are configured in a manner which reduces the potential for any closure of the port(s) during the rinseback procedure due to interconnecting one or more pumps with these ports. The port(s) is configured so as to have an orifice displaced from the radially outwardmost end of the port. This may be provided by configuring the end of the port to have the orifice positioned between two protrusions such that the orifice is recessed inwardly of the protrusions. Consequently, if the opposing portion of the blood processing vessel engages the protrusions during rinseback, the orifice is retained away from the blood processing vessel so as to not block the flow to the orifice.
In another embodiment relating to this thirteenth aspect, at least one narrowed portion within the blood processing vessel extends downwardly from at least one of the blood component outlet ports interfacing with the sidewall of the blood processing vessel toward a lower portion of the blood processing vessel. As such, during rinseback a drawing-like action, for instance achieved by pumping from the blood processing vessel out the blood component outlet port(s), is initiated in a lower portion of the blood processing vessel where the contents of the blood processing vessel will be if rotation of the channel housing is terminated during rinseback as preferred. A second narrowed portion may extend downwardly from the noted blood component outlet port such that one passageway extend away from the port in opposing directions and such that the drawing-like action is initiated in two displaced locations.
A fourteenth aspect of the present invention relates to facilitating insertion/loading and removal of a blood processing vessel to and from, respectively, a channel associated with a channel housing upon completion of an apheresis procedure. Generally, the blood processing vessel may be removed from and loaded into the channel by engaging structure which does not have any flow therethrough during the apheresis procedure. This may be achieved by interconnecting at least one and preferably a plurality of tabs or the like with the blood processing vessel. These tabs extend beyond the fluid-containing volume of the blood processing vessel and preferably extend beyond the channel when the vessel is loaded within the channel. As such, the tab(s) may be grasped by the operator of the apheresis system to load and unload the blood processing vessel to/from the channel. These tabs or the like may be particularly useful when there is some resistance to insertion/removal of the blood processing vessel from the channel, such as when a lip is formed on the upper portion of the channel as discussed in relation to the second aspect.
A fifteenth aspect of the present invention relates to providing a graphical operator interface for the procedure. This graphical operator interface pictorially displays to the operator at least a portion of the steps for the apheresis procedure, at least one of which requires some type of operator action. These steps may be pictorially displayed in the order in which they are to be performed. In order to further enhance operator recognition of the ordering of the pictorially displayed apheresis steps, the pictorials may also be numbered. Although the pictorials may alone convey to the operator the desired/required action, short textual descriptions may also be used in combination with the pictorials.
The pictorials may also be utilized to indicate the status of the apheresis procedure to the operator, such as by color or shade differentiation. For instance, three-way color or xe2x80x9cshadexe2x80x9d differentiation (e.g, in the case of colors using three different colors, and in the case of shade using the same general color but different levels of xe2x80x9cdarknessxe2x80x9d) may be utilized to indicate to the operator one of three conditions pertains to the step(s) associated with a particular pictorial. One color or shade may be utilized to indicate that the step(s) associated with the pictorial are untimely (e.g, not yet ready for execution), while another color or shade may be utilized to indicate that the step(s) associated with the pictorial are timely (e.g, ready for execution and/or are currently being executed), while yet another color or shade may be utilized to indicate that the step(s) associated with the pictorial have been executed. The status may also be conveyed by providing further indicia that the step(s) associated with a given pictorial have been completed.
The pictorials may further function as an operator input device. For instance, touch screen principles may be utilized such that the operator will touch one of the pictorials on the display when the operator is ready to execute the step(s) associated with the pictorial. This touch screen activation may generate one or more additional pictorials which graphically convey to the operator one or more steps or substeps which need to be undertaken at that particular time in the apheresis procedure.
A sixteenth aspect of the present invention also relates to an interface between the apheresis system and the operator. One embodiment of this sixteenth aspect is a method which includes the steps of instructing the apheresis system to address a first condition associated with the apheresis system by performing a first protocol. Typically, this xe2x80x9cfirst conditionxe2x80x9d will be some type of problem associated with the apheresis system which may be resolved in a multiplicity of ways (e.g, at least two), such as by performing the first protocol or by performing a second protocol. That is, the methodology relates to xe2x80x9cprogrammingxe2x80x9d the apheresis system to address or xe2x80x9ccorrectxe2x80x9d the first condition in one out of a plurality of ways and which does not allow/require the operator to make any decisions regarding how to address or xe2x80x9ccorrectxe2x80x9d the first condition.
In this embodiment of the sixteenth aspect, the methodology includes the steps of introducing blood into a blood separation device, separating the blood into a plurality of blood component types, and removing at least one of the blood component types from the device. The methodology also includes the step of identifying the existence of the first condition relating to the apheresis system and thereafter having the apheresis system perform the first protocol. This xe2x80x9cidentificationxe2x80x9d of the first condition may be based upon the operator observing the first condition and inputting information relating to the existence of the first condition to the apheresis system. This methodology may be effectively integrated into and/or utilize the graphical interface discussed above in relation to the fifteenth aspect of the invention.
Another embodiment relating to this sixteenth aspect relates to the apheresis system utilizing the operator to address potential problems associated with the apheresis procedure. A method of this sixteenth aspect includes the steps of introducing blood to the blood separation device, separating the blood into a plurality of blood component types, and removing at least one of these blood component types from the blood separation device. The method further includes the step of detecting the potential existence of a xe2x80x9cfirst conditionxe2x80x9d associated with the apheresis procedure. This xe2x80x9cfirst conditionxe2x80x9d is typically some potential problem and may be detected by the system itself (e.g, through appropriate detectors/sensors/monitors), the operator, and/or the donor/patient. Once this first condition is detected, the operator is prompted by the apheresis system (e.g, via a computer interface) to perform an investigation of the system or a particular portion thereof. The operator is also prompted to specify the result of this investigation to the system. Based upon the operator""s response to the investigation, the system may prompt the operator to take further action (e.g, to address the first condition in a particular manner). Once again, this methodology may be effectively integrated into and/or utilize the graphical interface discussed above in relation to the fifteenth aspect of the invention.
A seventeenth aspect of the present invention relates to a disposable assembly for extracorporeal blood processing that utilizes a single pressure sensing device to monitor positive and negative pressure changes in both the blood removal line and blood return line interconnectable with a donor/patient. In one embodiment, a pressure sensitive diaphragm member contacts blood on one side within a module of a molded cassette member, which cassette member may also include an integrally defined internal passageway fluidly interconnecting the module with both the blood removal and blood return lines. The use of a single pressure sensor reduces component costs and complexity, and yields significant accuracy advantages.
An eighteenth aspect of the present invention further pertains to a disposable assembly for extracorporeal blood processing having a single needle for removal/return of whole blood/uncollected blood components, a reservoir fluidly interconnected to the single needle for accumulating blood components, and a gas holding means fluidly interconnected to the reservoir for receiving gas from the reservoir and returning the gas to the reservoir as the reservoir cyclically accumulates and disposes uncollected blood components during a blood processing operation. In one embodiment, the reservoir is integrally defined within a molded cassette member. The provision of a gas holding means avoids a high internal pressure buildup as the reservoir is filled with returned blood components, thereby reducing gas entrainment at the liquid/gas interface and lowering the seal requirements for the reservoir and interconnected components.
A nineteenth aspect of the present invention relates to an extracorporeal blood processing device which includes a cassette member having a reservoir for accumulating uncollected blood components, and upper and lower ultrasonic sensors positionable adjacent to the reservoir and being responsive to the presence or absence, respectively, of fluid adjacent thereto within the reservoir to trigger the start and stop of blood return cycles. In a related aspect, each of the upper and lower ultrasonic sensors may advantageously comprise a contact surface for direct, dry-docking with the reservoir, thereby avoiding the need for the use of a docking gel or other like coupling medium.
A twentieth aspect of the present invention relates to an extracorporeal blood processing device that comprises a cassette member having a reservoir, at least first and second flexible tubing lines adjacently interconnected to the cassette member in predetermined spaced relation, a collection means interconnected to one of the flexible tubing lines, and an interfacing valve assembly having a moveable member selectively positionable to occlude one of the tubings lines, such that in a first mode of operation a separated blood component will be collected in the collection means, and in a second mode of operation the separated blood component will be diverted into the reservoir. In one embodiment, multiple sets of corresponding first and second tubing lines/collection means/and valve assemblies are provided, with each of the sets providing for selective diversion of a blood component into a separate collection means or common reservoir. Utilization of this arrangement yields a compact disposable that can be readily mounted relative to the divert valve assemblies in a reliable manner.
A twenty-first aspect of the present invention relates to loading of a disposable cassette member having a plurality of tubing loops extending therefrom relative to a plurality of flow control devices and at least one sensing device for extracorporeal blood processing. A mounting means is employed for selectively, securably and supportably receiving the cassette member in a substantially fixed position relative thereto, and the mounting means is selectively moveable between first and second locations wherein upon moving the mounting means from the first to second location, the tubing loops move into an operative position with corresponding ones of the flow control devices and the cassette member moves into a proper position for operation of the sensing means. In one embodiment, the sensing means includes at least one pressure sensor for monitoring the fluid pressure within a blood removal passageway of the cassette member, and further includes ultrasonic sensors for monitoring the fluid level of accumulated, uncollected blood components within a reservoir of the cassette.